Plasmon excitation by charged particles moving near a solid surface

The interaction of fast charged particles with a semi-infinite medium is described using both quantum-mechanical and semiclassical dielectric formulations. We consider the coupling with bulk and surface excitations for arbitrary trajectories of the particle and apply the solutions to several cases of special interest. Interference effects in bulk and surface excitations for some particular trajectories are described. We analyze in detail the process of reflection-electron-energy-loss spectroscopy, obtaining results for the probabilities of multiple bulk-and surface-plasmon excitations. The calculations are compared with available experimental results, showing a good description of the angular dependence of the excitation phenomenon.